Molecular layer deposition of amorphous carbon films

ABSTRACT

Methods of forming carbon polymer films are disclosed. Some methods are advantageously performed at lower temperatures. The substrate is exposed to a first carbon precursor to form a substrate surface with terminations based on the reactive functional groups of the first carbon precursor and exposed to a second carbon precursor to react with the surface terminations and form a carbon polymer film. Processing tools and non-transitory memories to perform the process are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/986,768, filed Mar. 8, 2020, the entire disclosure of which is herebyincorporated by reference herein.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to methods fordepositing or forming amorphous carbon films. Some embodiments of thedisclosure relate to molecular layer deposition (MLD) processes forforming amorphous carbon films.

BACKGROUND

Carbon-based films are important for semiconductor patterningapplications, especially as hard mask materials. Most hard mask filmsare grown by plasma-enhanced chemical vapor deposition (PECVD). ThesePECVD films are typically used for applications using blanketdeposition.

Another potential use of carbon-based films is as graphitic films forback-end-of-line (BEOL) barrier layers. Currently, carbon-based filmsare grown by physical vapor deposition (PVD) or PECVD processes.Conventional processes can form high quality carbon films but filmconformality remains an issue. The inability to deposit a conformal filmlimits the usefulness of these carbon-based films.

Accordingly, there is a need for methods of depositing carbon-basedfilms with improved conformality.

SUMMARY

One or more embodiments of the disclosure are directed to a method offorming a carbon polymer films. The method comprises exposing asubstrate to a first carbon precursor to form a first precursorterminated surface on the substrate. The first precursor terminatedsurface is exposed to a second carbon precursor to form a carbon polymerfilm on the substrate.

Additional embodiments of the disclosure are directed to processingtools comprising a central transfer station with at least one depositionchamber and at least one annealing chamber connected to a side of thecentral transfer station, and a controller. The controller has one ormore of: a configuration to move a substrate from the central transferstation to the at least one deposition chamber; a configuration to movea substrate from the at least one deposition chamber to the centraltransfer station; a configuration to move a substrate from the centraltransfer station to the at least one annealing chamber; a configurationto move a substrate from the at least one annealing chamber to thecentral transfer station; a configuration to expose a substrate to afirst carbon precursor to form a first precursor terminated surface onthe substrate; a configuration to expose the substrate to a secondcarbon precursor to react with the first precursor terminated surface toform a carbon polymer film on the substrate; a configuration to exposethe carbon polymer film on a substrate to a plasma treatment; and aconfiguration to anneal the carbon polymer film.

Further embodiments of the disclosure are directed to non-transitorycomputer readable medium including instructions, that, when executed bya controller of a processing chamber, causes the processing chamber toperform operations to: expose a substrate to a first carbon precursor ina processing chamber; purge the processing chamber of the first carbonprecursor; expose the substrate a second carbon precursor in theprocessing chamber; purge the processing chamber of the second carbonprecursor; move the substrate from the processing chamber to anannealing chamber; and/or anneal the substrate in the annealing chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 illustrates a process flow diagram of a method according to oneor more embodiments of the disclosure;

FIG. 2 illustrates a process flow diagram of a method according one ormore embodiments of the disclosure;

FIG. 3 illustrates a substrate feature with conformal carbon polymerfilm according to one or more embodiment of the disclosure; and

FIG. 4 illustrates a cluster tool according to one or more embodiments.

DETAILED DESCRIPTION

Before describing several exemplary embodiments of the disclosure, it isto be understood that the disclosure is not limited to the details ofconstruction or process steps set forth in the following description.The disclosure is capable of other embodiments and of being practiced orbeing carried out in various ways.

As used in this specification and the appended claims, the term“substrate” refers to a surface, or portion of a surface, upon which aprocess acts. It will also be understood by those skilled in the artthat reference to a substrate can also refer to only a portion of thesubstrate, unless the context clearly indicates otherwise. Additionally,reference to depositing on a substrate can mean both a bare substrateand a substrate with one or more films or features deposited or formedthereon

A “substrate” as used herein, refers to any substrate or materialsurface formed on a substrate upon which film processing is performedduring a fabrication process. For example, a substrate surface on whichprocessing can be performed include materials such as silicon, siliconoxide, strained silicon, silicon on insulator (SOI), carbon dopedsilicon oxides, amorphous silicon, doped silicon, germanium, galliumarsenide, glass, sapphire, and any other materials such as metals, metalnitrides, metal alloys, and other conductive materials, depending on theapplication. Substrates include, without limitation, semiconductorwafers. Substrates may be exposed to a pretreatment process to polish,etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure and/orbake the substrate surface. In addition to film processing directly onthe surface of the substrate itself, in the present disclosure, any ofthe film processing steps disclosed may also be performed on anunderlayer formed on the substrate as disclosed in more detail below,and the term “substrate surface” is intended to include such underlayeras the context indicates. Thus for example, where a layer or partiallayer has been deposited onto a substrate surface, the exposed surfaceof the newly deposited layer may also be described as the substratesurface. In one or more embodiments, the substrate comprises on or moreof titanium nitride (TiN), silicon (Si), cobalt (Co), titanium (Ti),silicon dioxide (SiO₂), copper (Cu), and black diamond (BD).

One or more embodiments of the disclosure are directed to methods forforming carbon films. The terms “carbon film” and “carbon-based films”are used interchangeably herein. In some embodiments, carbon films aredeposited by a molecular layer deposition (MLD) process. Someembodiments of the disclosure advantageously provide methods fordepositing carbon films with increased conformality. By MLD,conformality can be increased at the cost of thermal stability.Typically, polymer condensation reactions take place at lowertemperatures as the monomeric species desorb from the substrates atelevated temperatures. Therefore, carbon-based films deposited by MLDare generally unstable at higher temperatures due, in part, to poordensity of the film. In some embodiments, the thermal stability of thefilm is increased by plasma post-deposition processes.

Molecular layer deposition is a gas-phase self-limiting techniquesimilar to atomic layer deposition (ALD). Like ALD, MLD processesgenerally include sequential self-limiting surface reactions to deposita film. In MLD processes, the precursors can include organic compounds,rather than metal compounds; although metal species can be used. Theorganic compounds of MLD processes can include bifunctional organicmolecules, enabling film growth by a polymerization-type reaction.

Due to self-limiting behavior of MLD processes, conformal films can beachieved. A “conformal film”, as used herein, refers to a film withsubstantially equal thicknesses at the tops, sides and bottoms ofsubstrate surface features (e.g., trenches, vias). In some embodiments,a “conformal film” has a thickness at the top of a feature (outside ofthe feature) that is within ±20%, 15%, 10%, 5%, 2% or 1%, based on anaverage thickness. While conformal films can be formed, MLD-based filmsare often thermally unstable above ˜200° C., which is significantlylower than the common target stability of ˜400° C. Some embodiments ofthe disclosure advantageously provide MLD carbon-based films withinstability greater than 200° C., 250° C., 300° C. or higher. Someembodiments provide methods to deposit C-based films with thermalstability greater than or equal to 400° C.

Some embodiments of the disclosure advantageously provide methods fordepositing carbon-based films with tunable carbon (C), hydrogen (H),nitrogen (N) and/or oxygen (O) ratios. Some embodiments use differentmonomers with different C, H, N and O ratios, enabling better tuning ofthe material properties. In some embodiments, carbon-based films aredeposited with tunable C, H, N and O ratios that withstand 400° C.annealing. Some embodiments provide plasma enhanced MLD depositions ofhigh quality carbon-based films with high thermal resistance.

One or more embodiments of the disclosure are directed to methods togrow conformal carbon-based films on high aspect ratio (HAR) structureswith a depth greater than one micron (1 μm). Some embodiments providemethods to form conformal carbon-based films on HAR structures withcritical dimension (CD) of ˜300 nm.

One or more embodiments of the disclosure provide carbon-based films byplasma-enhanced molecular layer deposition (PEMLD or PE-MLD). In someembodiments, carbon-based films are deposited with thermal stabilityimproved to ˜400° C. by using plasma enhanced MLD growth.

The MLD methods of one or more embodiments use one or more polymerizableprecursors to deposit amorphous carbon films. Some embodiments of thedisclosure provide methods for forming amorphous carbon films withimproved thickness control.

In an exemplary reaction, 1,4-phenylene diisocyanate (DIC) and ethylenediamine (EDA) are used to form a carbon polymer film with a chemicalformula [C₁₀H₁₂N₄O₂]_(n). The growth per cycle (GPC) of some embodimentsdecreases with pedestal temperature. In some embodiments, the GPCsaturates at purge times of 30 seconds or greater, indicative of an ALDtype process. In some embodiments, the film formed demonstrates thepresence of C, H, N and O in the film, by FTIR analysis at 80° C. Insome embodiments, x-ray photoelectron spectroscopy (XPS) analysis at 80°C. shows a carbon rich film deposited with a maximum carbon content ofabout 81% (or greater). In some embodiments, the elemental surface scanconfirms similar compositions for thinner films. In some embodiments,the films are thermally stable up to 200° C., or even up to 300° C.

Some embodiments use thermal annealing and/or a plasma treatment toimprove thermal stability of the deposited film. In some embodiments,post-deposition treatment densifies or alters the film properties tomake the film more thermally stable. In some embodiments, a plasmatreatment (e.g., nitrogen plasma) is performed after each, or several,MLD cycles.

According to one or more embodiments, the method uses a molecular layerdeposition (ALD) process. In such embodiments, the substrate surface isexposed to the precursors (or reactive gases) sequentially orsubstantially sequentially. As used herein throughout the specification,“substantially sequentially” means that a majority of the duration of aprecursor exposure does not overlap with the exposure to a co-reagent,although there may be some overlap. As used in this specification andthe appended claims, the terms “precursor”, “reactant”, “reactive gas”and the like are used interchangeably to refer to any gaseous speciesthat can react with the substrate surface.

“Molecular layer deposition”, as used herein, refers to the sequentialexposure of two or more reactive compounds to deposit a layer ofmaterial on a substrate surface. The substrate, or portion of thesubstrate, is exposed separately to the two or more reactive compoundswhich are introduced into a reaction zone of a processing chamber. In atime-domain MLD process, exposure to each reactive compound is separatedby a time delay to allow each compound to adhere and/or react on thesubstrate surface and then be purged from the processing chamber. Thesereactive compounds are said to be exposed to the substrate sequentially.In a spatial MLD process, different portions of the substrate surface,or material on the substrate surface, are exposed simultaneously to thetwo or more reactive compounds so that any given point on the substrateis substantially not exposed to more than one reactive compoundsimultaneously. As used in this specification and the appended claims,the term “substantially” used in this respect means, as will beunderstood by those skilled in the art, that there is the possibilitythat a small portion of the substrate may be exposed to multiplereactive gases simultaneously due to diffusion, and that thesimultaneous exposure is unintended.

In one aspect of a time-domain MLD process, a first reactive gas (i.e.,a first precursor or compound A, e.g. aromatic precursor) is pulsed intothe reaction zone followed by a first time delay. Next, a secondprecursor or compound B (e.g. oxidant) is pulsed into the reaction zonefollowed by a second delay. During each time delay, a purge gas, such asargon, is introduced into the processing chamber to purge the reactionzone or otherwise remove any residual reactive compound or reactionby-products from the reaction zone. Alternatively, the purge gas mayflow continuously throughout the deposition process so that only thepurge gas flows during the time delay between pulses of reactivecompounds. The reactive compounds are alternatively pulsed until adesired film or film thickness is formed on the substrate surface. Ineither scenario, the MLD process of pulsing compound A, purge gas,compound B and purge gas is a cycle. A cycle can start with eithercompound A or compound B and continue the respective order of the cycleuntil achieving a film with the predetermined thickness.

In an embodiment of a spatial MLD process, a first reactive gas andsecond reactive gas (e.g., nitrogen gas) are delivered simultaneously tothe reaction zone but are separated by an inert gas curtain and/or avacuum curtain. The substrate is moved relative to the gas deliveryapparatus so that any given point on the substrate is exposed to thefirst reactive gas and the second reactive gas.

A “pulse” or “dose” as used herein is intended to refer to a quantity ofa source gas that is intermittently or non-continuously introduced intothe process chamber. The quantity of a particular compound within eachpulse may vary over time, depending on the duration of the pulse. Aparticular process gas may include a single compound or amixture/combination of two or more compounds, for example, the processgases described below.

The durations for each pulse/dose are variable and may be adjusted toaccommodate, for example, the volume capacity of the processing chamberas well as the capabilities of a vacuum system coupled thereto.Additionally, the dose time of a process gas may vary according to theflow rate of the process gas, the temperature of the process gas, thetype of control valve, the type of process chamber employed, as well asthe ability of the components of the process gas to adsorb onto thesubstrate surface. Dose times may also vary based upon the type of layerbeing formed and the geometry of the device being formed. A dose timeshould be long enough to provide a volume of compound sufficient toadsorb/chemisorb onto substantially the entire surface of the substrateand form a layer of a process gas component thereon.

FIG. 1 illustrates a process flow diagram of a method 100 in accordancewith one or more embodiments of the disclosure. The method 100illustrated in FIG. 1 is representative of an molecular layer deposition(MLD) process, in which the reactive gases are exposed to the substrateseparately to avoid gas phase reactions between the reactive gases.

With reference to FIG. 1 , the method 100 comprises a deposition cycle110. The method 100 begins at optional operation 102 by preparing thesubstrate to be processed. In some embodiments, preparing the substrate102 includes a pre-treatment operation. The pre-treatment can be anysuitable pre-treatment known to the skilled artisan. Suitablepre-treatments include, but are not limited to, pre-heating, cleaning,soaking, native oxide removal, or deposition of an adhesion layer (e.g.titanium nitride (TiN)). In some embodiments, the pre-treatment processcomprises a process that forms amine terminations on the substratesurface. In some embodiments, the pre-treatment process soaks thesubstrate in the same reactive species used as the second carbonprecursor, as described further below.

At deposition 110, a process is performed to deposit a carbon polymerfilm on the substrate (or substrate surface). In some embodiments, theprocess is performed to deposit a carbon polymer hard mask on thesubstrate. The deposition 110 process illustrated in FIG. 1 can beperformed in a time-domain type process or a spatially separatedprocess.

At operation 112, the substrate (or substrate surface) is exposed to afirst carbon precursor to form a first precursor terminated surface onthe substrate. The first precursor terminated surface has an activesite, region or moiety that is available for reaction with a differentreactive species. The first carbon precursor does not react with theactive site, region or moiety of the first precursor terminated surfaceso that a self-limiting reaction occurs.

The first carbon precursor of some embodiments comprises an organiccompound. In some embodiments, the first carbon precursor comprises anaromatic compound. In some embodiments, the first carbon precursorcomprises more than one functional group. As used in this manner, afunctional group is any reactive region or moiety of the compound thatcan react with either the substrate surface or with a second reactivespecies. In some embodiments, the first carbon precursor comprises twofunctional groups. In some embodiments, the first carbon precursorcomprises two of the same functional groups. The functional groups canbe any suitable functional groups capable of reacting with the substratesurface and/or the second carbon precursor, as described below. Suitablefunctional groups include, but are not limited to, cyano (—CN), cyanate(—OCN), isocyanate (—NCO), thiocyanate (—SCN), isothiocyanate (—NCS),and/or amines (—NR₂). In some embodiments, the first precursor comprisesor consists essentially of 1,4-phenylene diisocyanate (DIC). As used inthis specification and the appended claims, the term “consistsessentially of” means that the reactive species in the subject reactionor process step is greater than or equal to about 95%, 98%, 99% or 99.5%of the stated species, on a molar basis. In some embodiments, the firstprecursor terminated surface comprises isocyanate terminations (alsoreferred to as isocyanoto terminations or groups).

In some embodiments, the first precursor comprises an aromatic compound.As used herein, in one or more embodiments, the term “aromaticprecursor” or “aromatic compound” refers to precursors that arearomatic. As recognized by one of skill in the art, aromaticity is aproperty of cyclic (ring-shaped), planar (flat) structures with a ringof resonance bonds that gives increased stability compared to othergeometric or connective arrangements with the same set of atoms.Aromatic molecules are very stable, and do not break apart easily toreact with other substances. Aromaticity describes a conjugated systemoften made of alternating single and double bonds in a ring. Thisconfiguration allows for the electrons in the molecule's pi system to bedelocalized around the ring, increasing the molecule's stability.

In one or more embodiments, the aromatic precursor can comprise anyaromatic precursor known to the skilled artisan. In some embodiments,the aromatic precursor comprises one or more of benzene, substitutedbenzene, naphthalene, substituted naphthalene, anthracene, andsubstituted anthracene. In one or more embodiments, the aromaticprecursor may be substituted with one or more alkyl group, one or morealkoxy group, one or more vinyl group, one or more silane group, one ormore amine group, or one or more halide.

Unless otherwise indicated, the term “lower alkyl,” “alkyl,” or “alk” asused herein alone or as part of another group includes both straight andbranched chain hydrocarbons, containing 1 to 20 carbons, in the normalchain, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl,isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl,2,2,4-trimethyl-pentyl, nonyl, decyl, undecyl, dodecyl, the variousbranched chain isomers thereof, and the like. Such groups may optionallyinclude up to 1 to 4 substituents.

As used herein, the term “alkoxy” includes any of the above alkyl groupslinked to an oxygen atom.

As used herein, the terms “vinyl” or “vinyl-containing” refer to groupscontaining the vinyl group (—CH═CH₂).

As used herein, the term “amine” relates to any organic compoundcontaining at least one basic nitrogen atom, e.g. NR′₂, wherein whereinR′ is independently selected from hydrogen (H) or alkyl.

As used herein, the term “silane” refers to a compound SiR′₃, wherein R′is independently selected from hydrogen (H) or alkyl.

As used herein, the term “halide” refers to a binary phase, of which onepart is a halogen atom and the other part is an element or radical thatis less electronegative than the halogen, to make a fluoride, chloride,bromide, iodide, or astatide compound. A halide ion is a halogen atombearing a negative charge. As known to those of skill in the art, ahalide anion includes fluoride (F−), chloride (Cl−), bromide (Br−),iodide (I−), and astatide (At−).

The substrate may be any substrate known to one of skill in the art. Inone or more embodiments, the substrate comprises on or more of titaniumnitride (TiN), silicon (Si), cobalt (Co), titanium (Ti), silicon dioxide(SiO₂), copper (Cu), and black diamond (BD).

The substrate can be maintained at any suitable temperature dependingon, for example, the thermal budget of the device being formed, thereactive species, degradation temperatures, etc. In some embodiments,the substrate is maintained at a temperature less than 100° C. In someembodiments, the substrate is maintained at a temperature in the rangeof 50° C. to 100° C., or in the range of 60° C. to 95° C., or in therange of 70° C. to 85° C.

At operation 114, the processing chamber is purged. Purging (i.e.creating a vacuum) can be accomplished with any suitable gas that is notreactive with the substrate, film on the substrate, and/or processingchamber walls. Suitable purge gases include, but are not limited to, N₂,He, and Ar. The purge gas may be used to purge the processing chamber ofthe aromatic precursor, and/or the oxidant. In some embodiments, thesame purge gas is used for each purging operation. In other embodiments,a different purge gas is used for the various purging operations.

At operation 114, the processing chamber is purged to remove unreactedaromatic precursor, reaction products and by-products. As used in thismanner, the term “processing chamber” also includes portions of aprocessing chamber adjacent the substrate surface without encompassingthe complete interior volume of the processing chamber. For example, ina sector of a spatially separated processing chamber, the portion of theprocessing chamber adjacent the substrate surface is purged of thetellurium precursor by any suitable technique including, but not limitedto, moving the substrate through a gas curtain to a portion or sector ofthe processing chamber that contains none or substantially none of thearomatic precursor. In some embodiments, purging the processing chambercomprises flowing a purge gas over the substrate. In some embodiments,the portion of the processing chamber refers to a micro-volume or smallvolume process station within a processing chamber. The term “adjacent”referring to the substrate surface means the physical space next to thesurface of the substrate which can provide sufficient space for asurface reaction (e.g., precursor adsorption) to occur.

At operation 116, the substrate is exposed to a second carbon precursor.The second carbon precursor of some embodiments is a different compoundthan the first carbon precursor. The second carbon precursor reacts withthe first precursor terminated surface to form a carbon polymer film onthe substrate. In some embodiments, the second carbon precursorcomprises a compound with two or more functional groups. In someembodiments, the second carbon precursor comprises two functionalgroups. In some embodiments, the second carbon precursor comprises twoof the same functional groups. The functional groups of the secondcarbon precursor can be any suitable functional groups capable ofreacting with the substrate surface, the first precursor terminatedsurface and/or the first carbon precursor. Suitable functional groupsinclude, but are not limited to, cyano (—CN), cyanate (—OCN), isocyanate(—NCO), thiocyanate (—SCN), isothiocyanate (—NCS), aldehyde (—CHO), acylchloride (—COCl), acid anhydride (—C(O)OC(O)—), amines (—NR₂) and/oramides (—C(O)NR₂), where each R is independently selected from hydrogen,C1-C6 alkyl group. In some embodiments, the second carbon precursorcomprises or consists essentially of one or more of ethylene diamine(EDA) or phenylene diamine (PDA).

At operation 118, the processing chamber is purged of unreacted secondcarbon precursor. Purging (i.e. creating a vacuum) can be accomplishedwith any suitable gas that is not reactive with the substrate, film onthe substrate, and/or processing chamber walls. Suitable purge gasesinclude, but are not limited to, N₂, He, and Ar. The purge gas may beused to purge the processing chamber of the aromatic precursor, and/orthe oxidant. In some embodiments, the same purge gas is used for eachpurging operation. In other embodiments, a different purge gas is usedfor the various purging operations.

In one or more embodiments, the deposition process is carried out in aprocess volume at pressures in the range of 0.1 mTorr to 100 Torr, or inthe range of 1 mTorr to 1 Torr, or at a pressure of about 0.1 mTorr,about 1 mTorr, about 10 mTorr, about 100 mTorr, about 500 mTorr, about 1Torr, about 2 Torr, about 3 Torr, about 4 Torr, about 5 Torr, about 6Torr, about 7 Torr, about 8 Torr, about 9 Torr, and about 10 Torr.

The deposition cycle 110 may be performed until a predeterminedthickness of carbon polymer film has been formed. At operation 120, thethickness of the formed carbon polymer film is evaluated to determine ifit has reached the predetermined thickness. If not, the method 100repeats deposition cycle 110, returning to operation 112 for furtherformation. If the predetermined thickness has been reached, the method100 moves to optional post processing steps at operation 130, or themethod 100 ends.

The optional post-processing operation 130 can be, for example, aprocess to modify film properties (e.g., annealing) or a further filmdeposition process (e.g., additional ALD, MLD or CVD processes) to growadditional films. In some embodiments, the optional post-processingoperation 130 can be a process that modifies a property of the depositedfilm. In some embodiments, the optional post-processing operation 130comprises annealing the as-deposited film. In some embodiments,annealing is done at temperatures in the range of about 100° C. to about1100° C., or at a temperature greater than 300° C., 400° C., 500° C.,600° C., 700° C., 800° C., 900° C. or 1000° C. In some embodiments, thedeposited film is plasma annealed. In some embodiments, the plasmaanneal is any suitable type of plasma including, but not limited to, isconductively coupled plasma (CCP), inductively coupled plasma (ICP)using any suitable plasma power source (e.g., RF, DC, microwave). Insome embodiments, the plasma anneal comprises a plasma gas selected fromone or more of nitrogen (N₂), ammonia (NH₃) or argon (Ar). In someembodiments, the plasma anneal is a CCP without argon (Ar) as the plasmaspecies. In some embodiments, annealing the as-deposited film increasesthe density, decreases the resistivity and/or increases the purity ofthe film. Any suitable power can be used depending on, for example, thereactants, or the other process conditions. In some embodiments, theplasma is generated with a plasma power in the range of about 10 W toabout 3000 W. In some embodiments, the plasma is generated with a plasmapower less than or equal to about 3000 W, less than or equal to about2000 W, less than or equal to about 1000 W, less than or equal to about500 W, or less than or equal to about 250 W.

In some embodiments, the carbon polymer film is annealed at atemperature up to 400° C. In some embodiments, annealing the carbonpolymer film causes the carbon polymer film to decrease in thickness byan amount less than 20%, or 15% or 10%, relative to the as-depositedthickness.

In the embodiment illustrated in FIG. 1 , the carbon polymer film isoptionally treated with a plasma and/or annealing process after thepredetermined film thickness has been formed. In the embodimentillustrated in FIG. 2 , a plasma exposure process 219 is included in thedeposition 110 cycle. The plasma exposure process 219 of someembodiments is performed with each deposition cycle. In someembodiments, the plasma exposure process 219 is performed after a numberof deposition cycles in the range of 2 to 500, or in the range of 3 to200, or in the range of 4 to 100, or in the range of 5 to 50, of in therange of 5 to 25, or in the range of 5 to 20 cycles.

In some embodiments, the second carbon precursor is exposed to thesubstrate in a carrier or dilution gas selected from helium (He), argon(Ar), xenon (Xe), nitrogen (N₂), or hydrogen (H₂). The dilution gas ofsome embodiments comprises a compound that is inert gas relative to thereactants and substrate materials. In some embodiments, the dilution orcarrier gas is ignited into a plasma in a plasma enhanced MLD process.The plasma (e.g., capacitive-coupled plasma) may be formed from eithertop and bottom electrodes or side electrodes. The electrodes may beformed from a single powered electrode, dual powered electrodes, or moreelectrodes with multiple frequencies such as, but not limited to, 350KHz, 2 MHz, 13.56 MHz, 27 MHz, 40 MHz, 60 MHz and 100 MHz, being usedalternatively or simultaneously in a CVD system with any or all of thereactant gases listed herein to deposit a thin film of dielectric.

In some embodiments, as illustrated in FIG. 3 , the substrate 300comprises one or more features 310. A substrate feature 310 is anyintentionally formed recess or protrusion in the substrate surface.Suitable examples of features 310 include, but are not limited to,trenches, vias and pillars. The embodiment illustrated in FIG. 3 shows atrench with two sidewalls 312 and a bottom 314. The sidewalls 312 ofsome embodiments are a different material than the bottom 314. In someembodiments, the sidewalls 314 and the bottom 314 are the same material.In the embodiment shown, the bottom surface 315 of the feature 310 is ametal and the sidewall surfaces 313 are dielectrics. The skilled artisanwill recognize that this is merely one possible configuration and thatthe bottom and sidewalls can be any materials, either the same ordifferent. In some embodiments, the feature 310 has an aspect ratio(depth to width) greater than 5:1, 10:1, 15:1 or 20:1.

In some embodiments, as shown in FIG. 3 , the carbon polymer film 320 isa conformal film. For example, as shown, the thickness at the top T_(t),thickness on the sidewall T_(s) and thickness on the bottom T_(b) of thefeature 310 are illustrated as being the same.

In some embodiments, the carbon polymer film formed is an alternatingcopolymer. An alternating copolymer is a copolymer with a regularalternating pattern of two materials. For example, the material formedby the first carbon precursor alternating with the material formed bythe second carbon precursor.

In some embodiments, the carbon polymer film has carbon, nitrogen,oxygen and hydrogen atoms. In some embodiments, the carbon polymer filmconsists essentially of carbon, nitrogen, oxygen and hydrogen atoms. Asused in this manner, the term consists essentially of means that the sumof the stated elements is greater than or equal to 95%, 98%, 99% or99.5% of the total atomic makeup of the film. In some embodiments, thecarbon polymer film comprises or consists essentially of carbon,nitrogen and oxygen atoms. In some embodiments, the carbon polymer filmhas a carbon content in the range of 40% to 90%, or in the range of 50%to 80%, or in the range of 60% to 70%. In some embodiments, the carboncontent is greater than 30%, 40%, 50%, 60%, 70% or 80%. In someembodiments, the carbon polymer film has a nitrogen content in the rangeof 2% to 40%, or in the range of 3% to 35%, or in the range of 4% to30%, or in the range of 5% to 25%, or in the range of 8% to 20%. In someembodiments, the nitrogen content is greater than 1%, 2%, 3%, 4%, 5%,10%, 15% or 20%. In some embodiments, the carbon polymer film has anoxygen content in the range of 1% to 20%, or 2% to 18%, or 3% to 16% or4% to 14% or 5% to 12%. In some embodiments, the oxygen content isgreater than 1%, 2%, 3%, 4%, 5% or 6%.

In one or more embodiments, the deposition operation 110 is repeated toform a carbon polymer film having a predetermined thickness. In someembodiments, the deposition operation 110 is repeated to provide acarbon polymer film having a thickness greater than about 0.1 nm, or inthe range of from about 0.1 nm to about 1000 nm, including from about 10nm to about 500 nm, from about 10 nm to about 100 nm, from about 5 nm toabout 50 nm, from about 10 nm to about 50 nm, or from about 20 nm toabout 30 nm.

According to one or more embodiments, the substrate is subjected toprocessing prior to and/or after forming the layer. This processing canbe performed in the same chamber or in one or more separate processingchambers. In one or more embodiments, the substrate is then moved toanother processing chamber for further processing. The substrate can bemoved directly from the physical vapor deposition chambers to theseparate processing chamber, or it can be moved from the physical vapordeposition chambers to one or more transfer chambers, and then moved tothe separate processing chamber. Accordingly, the processing apparatusmay comprise multiple chambers in communication with a transfer station.An apparatus of this sort may be referred to as a “cluster tool” or“clustered system,” and the like.

Generally, a cluster tool is a modular system comprising multiplechambers which perform various functions including substratecenter-finding and orientation, degassing, annealing, deposition and/oretching. According to one or more embodiments, a cluster tool includesat least a first chamber and a central transfer chamber. The centraltransfer chamber may house a robot that can shuttle substrates betweenand among processing chambers and load lock chambers. The transferchamber is typically maintained at a vacuum condition and provides anintermediate stage for shuttling substrates from one chamber to anotherand/or to a load lock chamber positioned at a front end of the clustertool. Two well-known cluster tools which may be adapted for the presentinvention are the Centura® and the Endura®, both available from AppliedMaterials, Inc., of Santa Clara, Calif. However, the exact arrangementand combination of chambers may be altered for purposes of performingspecific steps of a process as described herein. Other processingchambers which may be used include, but are not limited to, cyclicallayer deposition (CLD), atomic layer deposition (ALD), chemical vapordeposition (CVD), physical vapor deposition (PVD), etch, pre-clean,chemical clean, thermal treatment such as RTP, plasma nitridation,degas, orientation, hydroxylation and other substrate processes. Bycarrying out processes in a chamber on a cluster tool, surfacecontamination of the substrate with atmospheric impurities can beavoided without oxidation prior to depositing a subsequent film.

According to one or more embodiments, the substrate is continuouslyunder vacuum or “load lock” conditions, and is not exposed to ambientair when being moved from one chamber to the next. The transfer chambersare thus under vacuum and are “pumped down” under vacuum pressure. Inertgases may be present in the processing chambers or the transferchambers. In some embodiments, an inert gas is used as a purge gas toremove some or all of the reactants. According to one or moreembodiments, a purge gas is injected at the exit of the depositionchamber to prevent reactants from moving from the deposition chamber tothe transfer chamber and/or additional processing chamber. Thus, theflow of inert gas forms a curtain at the exit of the chamber.

The substrate can be processed in single substrate deposition chambers,where a single substrate is loaded, processed and unloaded beforeanother substrate is processed. The substrate can also be processed in acontinuous manner, similar to a conveyer system, in which multiplesubstrate are individually loaded into a first part of the chamber, movethrough the chamber and are unloaded from a second part of the chamber.The shape of the chamber and associated conveyer system can form astraight path or curved path. Additionally, the processing chamber maybe a carousel in which multiple substrates are moved about a centralaxis and are exposed to deposition, etch, annealing, cleaning, etc.processes throughout the carousel path.

During processing, the substrate can be heated or cooled. Such heatingor cooling can be accomplished by any suitable means including, but notlimited to, changing the temperature of the substrate support andflowing heated or cooled gases to the substrate surface. In someembodiments, the substrate support includes a heater/cooler which can becontrolled to change the substrate temperature conductively. In one ormore embodiments, the gases (either reactive gases or inert gases) beingemployed are heated or cooled to locally change the substratetemperature. In some embodiments, a heater/cooler is positioned withinthe chamber adjacent the substrate surface to convectively change thesubstrate temperature.

The substrate can also be stationary or rotated during processing. Arotating substrate can be rotated continuously or in discreet steps. Forexample, a substrate may be rotated throughout the entire process, orthe substrate can be rotated by a small amount between exposures todifferent reactive or purge gases. Rotating the substrate duringprocessing (either continuously or in steps) may help produce a moreuniform deposition or etch by minimizing the effect of, for example,local variability in gas flow geometries.

Additional embodiments of the disclosure are directed to processingtools 900 for the formation of the devices and practice of the methodsdescribed, as shown in FIG. 4 . The cluster tool 900 includes at leastone central transfer station 921, 931 with a plurality of sides. A robot925, 935 is positioned within the central transfer station 921, 931 andis configured to move a robot blade and a wafer to each of the pluralityof sides.

The cluster tool 900 comprises a plurality of processing chambers 902,904, 906, 908, 910, 912, 914, 916, and 918, also referred to as processstations, connected to the central transfer station. The variousprocessing chambers provide separate processing regions isolated fromadjacent process stations. The processing chamber can be any suitablechamber including, but not limited to, a physical vapor depositionchamber, a UV curing chamber, an ICP chamber, an etching chamber, andthe like. The particular arrangement of process chambers and componentscan be varied depending on the cluster tool and should not be taken aslimiting the scope of the disclosure.

In some embodiments, the cluster tool 900 includes at least one physicalvapor deposition chamber. In some embodiments, the cluster tool 900includes a physical vapor deposition chamber having a remote plasmasource connected to the central transfer station.

In the embodiment shown in FIG. 3 , a factory interface 950 is connectedto a front of the cluster tool 900. The factory interface 950 includes aloading chamber 954 and an unloading chamber 956 on a front 951 of thefactory interface 950. While the loading chamber 954 is shown on theleft and the unloading chamber 956 is shown on the right, those skilledin the art will understand that this is merely representative of onepossible configuration.

The size and shape of the loading chamber 954 and unloading chamber 956can vary depending on, for example, the substrates being processed inthe cluster tool 900. In the embodiment shown, the loading chamber 954and unloading chamber 956 are sized to hold a wafer cassette with aplurality of wafers positioned within the cassette.

A robot 952 is within the factory interface 950 and can move between theloading chamber 954 and the unloading chamber 956. The robot 952 iscapable of transferring a wafer from a cassette in the loading chamber954 through the factory interface 950 to load lock chamber 960. Therobot 952 is also capable of transferring a wafer from the load lockchamber 962 through the factory interface 950 to a cassette in theunloading chamber 956. As will be understood by those skilled in theart, the factory interface 950 can have more than one robot 952. Forexample, the factory interface 950 may have a first robot that transferswafers between the loading chamber 954 and load lock chamber 960, and asecond robot that transfers wafers between the load lock 962 and theunloading chamber 956.

The cluster tool 900 shown has a first section 920 and a second section930. The first section 920 is connected to the factory interface 950through load lock chambers 960, 962. The first section 920 includes afirst transfer chamber 921 with at least one robot 925 positionedtherein. The robot 925 is also referred to as a robotic wafer transportmechanism. The first transfer chamber 921 is centrally located withrespect to the load lock chambers 960, 962, process chambers 902, 904,916, 918, and buffer chambers 922, 924. The robot 925 of someembodiments is a multi-arm robot capable of independently moving morethan one wafer at a time. In some embodiments, the first transferchamber 921 comprises more than one robotic wafer transfer mechanism.The robot 925 in first transfer chamber 921 is configured to move wafersbetween the chambers around the first transfer chamber 921. Individualwafers are carried upon a wafer transport blade that is located at adistal end of the first robotic mechanism.

After processing a wafer in the first section 920, the wafer can bepassed to the second section 930 through a pass-through chamber. Forexample, chambers 922, 924 can be uni-directional or bi-directionalpass-through chambers. The pass-through chambers 922, 924 can be used,for example, to cryo cool the wafer before processing in the secondsection 930, or allow wafer cooling or post-processing before movingback to the first section 920.

A system controller 990 is in communication with the first robot 925,second robot 935, first plurality of processing chambers 902, 904, 916,918 and second plurality of processing chambers 906, 908, 910, 912, 914.The system controller 990 can be any suitable component that can controlthe processing chambers and robots. For example, the system controller990 can be a computer including a central processing unit (CPU) 992,memory 994, inputs/outputs (I/O) 996, and support circuits 998. Thecontroller 990 may control the processing tool 900 directly, or viacomputers (or controllers) associated with particular process chamberand/or support system components.

In one or more embodiments, the controller 990 may be one of any form ofgeneral-purpose computer processor that can be used in an industrialsetting for controlling various chambers and sub-processors. The memory994 or computer readable medium of the controller 990 may be one or moreof readily available memory such as non-transitory memory (e.g. randomaccess memory (RAM)), read only memory (ROM), floppy disk, hard disk,optical storage media (e.g., compact disc or digital video disc), flashdrive, or any other form of digital storage, local or remote. The memory994 can retain an instruction set that is operable by the processor (CPU992) to control parameters and components of the processing tool 900.

The support circuits 998 are coupled to the CPU 992 for supporting theprocessor in a conventional manner. These circuits include cache, powersupplies, clock circuits, input/output circuitry and subsystems, and thelike. One or more processes may be stored in the memory 994 as softwareroutine that, when executed or invoked by the processor, causes theprocessor to control the operation of the processing tool 900 orindividual processing units in the manner described herein. The softwareroutine may also be stored and/or executed by a second CPU (not shown)that is remotely located from the hardware being controlled by the CPU992.

Some or all of the processes and methods of the present disclosure mayalso be performed in hardware. As such, the process may be implementedin software and executed using a computer system, in hardware as, e.g.,an application specific integrated circuit or other type of hardwareimplementation, or as a combination of software and hardware. Thesoftware routine, when executed by the processor, transforms the generalpurpose computer into a specific purpose computer (controller) thatcontrols the chamber operation such that the processes are performed.

In some embodiments, the controller 990 has one or more configurationsto execute individual processes or sub-processes to perform the method.The controller 990 can be connected to and configured to operateintermediate components to perform the functions of the methods. Forexample, the controller 990 can be connected to and configured tocontrol a molecular layer deposition chamber.

Processes may generally be stored in the memory 994 of the systemcontroller 990 as a software routine that, when executed by theprocessor, causes the process chamber to perform processes of thepresent disclosure. The software routine may also be stored and/orexecuted by a second processor (not shown) that is remotely located fromthe hardware being controlled by the processor. Some or all of themethod of the present disclosure may also be performed in hardware. Assuch, the process may be implemented in software and executed using acomputer system, in hardware as, e.g., an application specificintegrated circuit or other type of hardware implementation, or as acombination of software and hardware. The software routine, whenexecuted by the processor, transforms the general purpose computer intoa specific purpose computer (controller) that controls the chamberoperation such that the processes are performed.

In some embodiments, the system controller 990 has a configuration tocontrol a deposition chamber to deposit a film on a wafer at atemperature in the range of about 20° C. to about 400° C.

In one or more embodiments, a processing tool comprises: a centraltransfer station comprising a robot configured to move a wafer; aplurality of process stations, each process station connected to thecentral transfer station and providing a processing region separatedfrom processing regions of adjacent process stations, the plurality ofprocess stations comprising a physical vapor deposition chamber and aremote plasma source; a UV curing chamber; an ICP chamber; and acontroller connected to the central transfer station and the pluralityof process stations, the controller configured to activate the robot tomove the wafer between process stations, and to control a processoccurring in each of the process stations.

In some embodiments, the controller 990 has one or more of: aconfiguration to move a substrate from the central transfer station tothe at least one deposition chamber; a configuration to move a substratefrom the at least one deposition chamber to the central transferstation; a configuration to move a substrate from the central transferstation to the at least one annealing chamber; a configuration to move asubstrate from the at least one annealing chamber to the centraltransfer station; a configuration to expose a substrate to a firstcarbon precursor to form a first precursor terminated surface on thesubstrate; a configuration to expose the substrate to a second carbonprecursor to react with the first precursor terminated surface to form acarbon polymer film on the substrate; a configuration to expose thecarbon polymer film on a substrate to a plasma treatment; or aconfiguration to anneal the carbon polymer film.

Some embodiments of the disclosure are directed to non-transitorycomputer readable medium including instructions, that, when executed bya controller of a processing chamber, causes the processing chamber toperform operations to: expose a substrate to a first carbon precursor ina processing chamber; purge the processing chamber of the first carbonprecursor; expose the substrate a second carbon precursor in theprocessing chamber; purge the processing chamber of the second carbonprecursor; move the substrate from the processing chamber to anannealing chamber; and/or anneal the substrate in the annealing chamber.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the materials and methods discussed herein(especially in the context of the following claims) are to be construedto cover both the singular and the plural, unless otherwise indicatedherein or clearly contradicted by context. Recitation of ranges ofvalues herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate the materials and methods and does not pose a limitation onthe scope unless otherwise claimed. No language in the specificationshould be construed as indicating any non-claimed element as essentialto the practice of the disclosed materials and methods.

Reference throughout this specification to “one embodiment,” “certainembodiments,” “one or more embodiments” or “an embodiment” means that aparticular feature, structure, material, or characteristic described inconnection with the embodiment is included in at least one embodiment ofthe disclosure. Thus, the appearances of the phrases such as “in one ormore embodiments,” “in certain embodiments,” “in one embodiment” or “inan embodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the disclosure. In oneor more embodiments, the particular features, structures, materials, orcharacteristics are combined in any suitable manner.

Although the disclosure herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent disclosure. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present disclosure without departing from the spiritand scope of the disclosure. Thus, it is intended that the presentdisclosure include modifications and variations that are within thescope of the appended claims and their equivalents.

What is claimed is:
 1. A method of depositing a film, the methodcomprising: exposing a substrate to a first carbon precursor to form afirst precursor terminated surface on the substrate; exposing the firstprecursor terminated surface to a second carbon precursor to form aconformal carbon polymer film on the substrate; and annealing the carbonpolymer film at a temperature up to 400° C., wherein annealing thecarbon polymer film causes the carbon polymer film to decrease inthickness less than 20%.
 2. The method of claim 1, wherein the firstcarbon precursors comprises an aromatic compound.
 3. The method of claim1, wherein the first carbon precursor comprises two functional groups.4. The method of claim 3, wherein the two functional groups are the sameand are selected from the group consisting of cyano (—CN), cyanate(—OCN), isocyanate (—NCO), thiocyanate (—SCN), isothiocyanate (—NCS),aldehyde (—CHO), acyl chloride (—COCl), acid anhydride (—C(O)OC(O)—),amines (—NR₂) and amides (—C(O)NR₂), where each R is independentlyselected from hydrogen, C1-C6 alkyl group.
 5. The method of claim 1,wherein the first carbon compound comprises 1,4-phenylene diisocyanate(DIC).
 6. The method of claim 1, wherein the second carbon compoundcomprises two functional groups.
 7. The method of claim 6, wherein thetwo functional groups are the same.
 8. The method of claim 1, whereinthe second carbon compound comprises one or more of ethylene diamine(EDA) or phenylene diamine (PDA).
 9. The method of claim 1, wherein thecarbon polymer film is an alternating copolymer.
 10. The method of claim1, wherein the carbon polymer film has a carbon content in the range of40% to 90%, a nitrogen content in the range of 2% to 40% and an oxygencontent in the range of 1% to 20%.
 11. The method of claim 1, whereinthe substrate surface comprises one or more of silicon (Si), siliconnitride (SiN) or copper (Cu).
 12. The method of claim 1, wherein thesubstrate surface is pre-treated to form amine terminations.
 13. Themethod of claim 12, wherein the first precursor terminated surfacecomprises isocyanate terminations.
 14. The method of claim 1, whereinthe substrate comprises one or more surface features having an aspectratio greater than 5:1 and the carbon polymer film is a conformal film.15. The method of claim 1, further comprising exposing the carbonpolymer film to a plasma treatment to enhance thermal stability of thecarbon polymer film.
 16. The method of claim 1, wherein the substrate ismaintained at a temperature less than 100° C.